Example 5
This is the last example that explain how to build custom form widgets.
Change states
HTML
html
<form class="no-widget">
<select name="myFruit">
<option>Cherry</option>
<option>Lemon</option>
<option>Banana</option>
<option>Strawberry</option>
<option>Apple</option>
</select>
<div class="select" role="listbox">
<span class="value">Cherry</span>
<ul class="optList hidden" role="presentation">
<li class="option" role="option" aria-selected="true">Cherry</li>
<li class="option" role="option">Lemon</li>
<li class="option" role="option">Banana</li>
<li class="option" role="option">Strawberry</li>
<li class="option" role="option">Apple</li>
</ul>
</div>
</form>
CSS
css
.widget select,
.no-widget .select {
position: absolute;
left: -5000em;
height: 0;
overflow: hidden;
}
/* --------------- */
/* Required Styles */
/* --------------- */
.select {
position: relative;
display: inline-block;
}
.select.active,
.select:focus {
box-shadow: 0 0 3px 1px #227755;
outline: none;
}
.select .optList {
position: absolute;
top: 100%;
left: 0;
}
.select .optList.hidden {
max-height: 0;
visibility: hidden;
}
/* ------------ */
/* Fancy Styles */
/* ------------ */
.select {
font-size: 0.625em; /* 10px */
font-family: Verdana, Arial, sans-serif;
box-sizing: border-box;
padding: 0.1em 2.5em 0.2em 0.5em; /* 1px 25px 2px 5px */
width: 10em; /* 100px */
border: 0.2em solid #000; /* 2px */
border-radius: 0.4em; /* 4px */
box-shadow: 0 0.1em 0.2em rgba(0, 0, 0, 0.45); /* 0 1px 2px */
background: #f0f0f0;
background: linear-gradient(0deg, #e3e3e3, #fcfcfc 50%, #f0f0f0);
}
.select .value {
display: inline-block;
width: 100%;
overflow: hidden;
white-space: nowrap;
text-overflow: ellipsis;
vertical-align: top;
}
.select:after {
content: "▼";
position: absolute;
z-index: 1;
height: 100%;
width: 2em; /* 20px */
top: 0;
right: 0;
padding-top: 0.1em;
box-sizing: border-box;
text-align: center;
border-left: 0.2em solid #000;
border-radius: 0 0.1em 0.1em 0;
background-color: #000;
color: #fff;
}
.select .optList {
z-index: 2;
list-style: none;
margin: 0;
padding: 0;
background: #f0f0f0;
border: 0.2em solid #000;
border-top-width: 0.1em;
border-radius: 0 0 0.4em 0.4em;
box-shadow: 0 0.2em 0.4em rgba(0, 0, 0, 0.4);
box-sizing: border-box;
min-width: 100%;
max-height: 10em; /* 100px */
overflow-y: auto;
overflow-x: hidden;
}
.select .option {
padding: 0.2em 0.3em;
}
.select .highlight {
background: #000;
color: #ffffff;
}
JavaScript
js
// -------------------- //
// Function definitions //
// -------------------- //
function deactivateSelect(select) {
if (!select.classList.contains("active")) return;
const optList = select.querySelector(".optList");
optList.classList.add("hidden");
select.classList.remove("active");
}
function activeSelect(select, selectList) {
if (select.classList.contains("active")) return;
selectList.forEach(deactivateSelect);
select.classList.add("active");
}
function toggleOptList(select, show) {
const optList = select.querySelector(".optList");
optList.classList.toggle("hidden");
}
function highlightOption(select, option) {
const optionList = select.querySelectorAll(".option");
optionList.forEach((other) => {
other.classList.remove("highlight");
});
option.classList.add("highlight");
}
function updateValue(select, index) {
const nativeWidget = select.previousElementSibling;
const value = select.querySelector(".value");
const optionList = select.querySelectorAll(".option");
optionList.forEach((other) => {
other.setAttribute("aria-selected", "false");
});
optionList[index].setAttribute("aria-selected", "true");
nativeWidget.selectedIndex = index;
value.innerHTML = optionList[index].innerHTML;
highlightOption(select, optionList[index]);
}
function getIndex(select) {
const nativeWidget = select.previousElementSibling;
return nativeWidget.selectedIndex;
}
// ------------- //
// Event binding //
// ------------- //
window.addEventListener("load", () => {
const form = document.querySelector("form");
form.classList.remove("no-widget");
form.classList.add("widget");
});
window.addEventListener("load", () => {
const selectList = document.querySelectorAll(".select");
selectList.forEach((select) => {
const optionList = select.querySelectorAll(".option");
const selectedIndex = getIndex(select);
select.tabIndex = 0;
select.previousElementSibling.tabIndex = -1;
updateValue(select, selectedIndex);
optionList.forEach((option, index) => {
option.addEventListener("mouseover", () => {
highlightOption(select, option);
});
option.addEventListener("click", (event) => {
updateValue(select, index);
});
});
select.addEventListener("click", (event) => {
toggleOptList(select);
});
select.addEventListener("focus", (event) => {
activeSelect(select, selectList);
});
select.addEventListener("blur", (event) => {
deactivateSelect(select);
});
select.addEventListener("keyup", (event) => {
let index = getIndex(select);
if (event.keyCode === 27) {
deactivateSelect(select);
}
if (event.keyCode === 40 && index < optionList.length - 1) {
index++;
}
if (event.keyCode === 38 && index > 0) {
index--;
}
updateValue(select, index);
});
});
});